function Rectangle(name, width, height) {
  this.name = name;
  this.width = width;
  this.height = height;
}

const rect = new Rectangle('矩形one', 20, 10);
console.log(rect);
console.log(rect.__proto__);
console.log(rect.__proto__.constructor);
console.log(rect.toString());

const arr = [];
console.log(arr.__proto__);

const str = new String("fuck this world");
console.log(str.__proto__);

const obj = {};
console.log(obj.__proto__);

console.log(Object.getPrototypeOf(rect));